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E. w. KELLOGG AND c. w. RICE" RADIORECEIYING SYSTEM. APPLICATION FILED APR, 27, 192].

Patented Nov. 7, 1922. I

. dl l l F 371 Inventors: Edward-W. Kellogg. ChesterW Ri'ce,"

Thai? Attornfiy Patented Nov. 7, 1922.!

UNITED S AT s.-

' mace OFFIC EDWARD w. KELLOGG AND CHESTER w. men, OF SCHEL TECTADY, NEW YoRK,

ASSIGNORS '10 GENERAL ELECTRIC COMPANY,

A CORPORATION OF NEW YORK.

RADIORECEIVING SYSTEM.

Application filed April 27,

T all whom it concern Be'it known that we, EDWARD l/VIKELIJOGG and CHEs'rER WV. RICE, citizens of the United Which is especially adapted for the efficient reception of signals.

The object of our present invention is to provide a method of and means for utilizing an antenna of the form described in our prior application for the simultaneous reception of a plurality of signals of different Wave lengths. We have pointed out in the 2'5 above mentioned application that with a long receiving antenna extending in the general direction of transmission of the signaling waves to be received, signaling currents produced in the antenna by wlaves com-' 80 ing from any particulartransmitting station will be strongest'at the; end of the antenna farthest from the transmitting station, while currents produced by Waves coming from the opposite direction will be a minimum at that point. The antenna described is preferably aperiodic "so that the strength of the signaling currents produced therein is substantially independent of the wave length. Y i

In carrying out our invention, we utilize an antenna of this type and impress-from the antenna upon the input circuits of a plurality of electron discharge amplifiers potentials produced in the antenna at a se lected point. In order to improve the reception, we also provide means for impressing uponeach of these input circuits a currentseleoted from. another point in the antenna which will be of the proper intensity and phase to neutralize in each receiving set disturbing currents produced therein either by interference from undesired waves or by strays. Each of the output circuits of the amplifiers has associated therewith a resonant circuit which is tuned to the frequency 1921 Serial No. 464,787.

of one of the signaling waves which it is del slred to -receive, and these resonant circuits arte associated with the respective receiving se s.

- The-novel features which we believe to be characteristic of our invention are set forth 1n the appended claims, the invention itself, however, both. as to .its organization andmethod of operation, together with further ObJBCtS and advantages thereof, will best be understood by reference to the following de scriptlon taken in connection with the accompanylng drawings in which Figs. 1 and 2 show diagrammatically two different 'circuit arrangements whereby our invention ma be carried into effect.

n carrying out our invention, we make use of a. long horizontal receiving antenna made up of two conductors land 2 which are grounded at the ends. I In the drawings we have shown only one. end of these con ductors with the ground connection 3 at that end. If this antenna is constructed with distributed constants of such .value that the current wave therein travels at the same velocit-y as the ether wave, the current wave in the antenna Will gradually build up and become a maximum at the end farthest. from the transmitting station. If the velocity of the current wave in the antenna differs somewhat from that of the ether wave'then for a certain distance the waves will add but 'a point will finally be reached where one wave will be so far in advance of the other that the two will be in phase opposition. Interference will then occur and the current wave will start to decrease. In any case, the antenna should preferably be constructed with such constants that the length at which the current Wave becomes'maximum will be at least as great as a half wave length of the signaling wave to be received. Currents produced at the end "3 by ether waves traveling from that end to the opposite end will have substantially a zero value at the end 3 and will increase to a maximum value at the opposite end. In the same way currents produced by ether waves traveling from the opposite end toward the end 3 will have a minimum value at the opposite end and a maximum value at the end 3. Inorder to prevent reflection of the current waves flowing in theantenna from the ends, the ground connections may .bemade through resistances having a value substantially equal to the surge impedance of the antenna. In the present case we have indicated such a grounding resistance 4 at the end'3. of the A similar grounding resistance antenna. may be used at both endsof the antenna. if desired.

In Figs. land 2 we have indicated the receiving station as being located at the end the antenna. In order to beable to receive at this point currents produced by. waves traveling from the end 3 toward the opposite end, which consequently are a maxceiving apparatus.

' claimed in a copending I ward W. Kellogg, Serial No. 438,544, filed' The conductors 1 and 2 imum at the opposite end, the antenna conductors' maybe employed as a transmission line for transmitting slgnaling current from the opposite end of the antenna to the re- The manner in which this may be accomplished is described and application ofEd- January 20, 1921. form the two sides of a transmission line which is completed at the end 3 of the antpnnaby means of the two coils 5, 6. The 'point 7 between the two coils 5 and 6 being connected to ground at 3'and the midpoint of the secondary'ofthe transformer at the opposite end of the antenna by means of which the signaling currents are impressed upon the transmission line, being also con-.

nected to ground, substantially no current will be produced in thegro'und connection at 3 by the signaling currents conveyed over the transmission line from the opposit e 'eml.

The windings 8, 9 and 10 which are inductively related to th'e'coils 5. and 6,.are in- =cluded in'the input circuits of electron dis charge -amplifiers 11, 12 and 13.. Windings 14,15 and 16 areincluded in theloutput circuits of the amplifiers and are associated with resonant circuits 17, 18 and 19, these 0 pressed upon the respective receiving apparatus 20, 21 and '22,- which may be of any desired type. 1

The distributed inductance and capacity 'ofthe antenna do notremain constant, but change more or less with frequeny. This may be due to lesser depth of penetration into the earth at higher frequencies. It may to wave length, an adjustment of the damping also happen that th antenna will be partially unbalanced to signals and strays coming from the side except when the antenna length bears a definite relation to the wave length. If, therefore, the reception of sev-' eral signals is to be carried on simultaneously, and if these signals dilfer greatly in erties, v experience shows that at the end farthest resistance 4 may render the antenna perfectly unidirectional for only the wave length for which the damping resistance is adjusted. While when properly adjusted the antenna has decided unidirectional propmathematical analysis indicates and from the transmitting station small currents will under some conditions be produced by waves coming from the opposite direction even though the ground resistance, is prop erly adjusted to prevent reflection. For these reasons it is desirable in order to so cure the best results to balance out in the receiving circuit undesired currents produced by these different factors. This balancing action may be accomplished in the arran ements shown by connecting in series with-t eground connection at 3 the primary winding, 23 of a transformer the secondary winding 2 10f which is connected to an artificial transmission line made u of series inductance 25 and shunt capacities 26. The currents flowing to ground at 3 and impressed upon the artificial line, are currents built up on the antenna'conductorsin parallel by the ether waves 1 traveling from the opposite end toward the end 3. This arti ficial, line is closed at the end opposite the transformer winding 24 through a resistance 27, equal approximately to the surge impedance of the line so that no appreciable reflection can occur. The desired currents for neutralization purposes in the respective receiving circuits are impressed upon thein- .put circuits of theamplifiers '11, 12 and 13 from this artificial line. The phase of the neutralizing currents selected may be adjusted by varying the connections 28, 29 and 30. The intensity of these neutralizing currents may also be adjusted by means of the potentiometers 31, 32 and 33. Since the input circuit of these amplifiers takes practically no current there will be substantially no load u on these potentiometers or upon the secon ary windings 8, 9 and 10. This makes it possible to use poteniometers of such a high resistance in comparison with the impedance of the transmission line that the potentiometers represent a a negligible loadon the transmission line. The sliding contacts 28, 29, 30 can under these conditions be placed anywhere along the transmission 1 line without affecting theypotential at other points and thus disturbing the adjustment'of the other receiving sets. Winding, 23 is shunted by a'variable resistance 34 and the impedance of the input of the artificial line is practically independent of the frequency and equivalent to a simple resistance. This makes it possible to adjust the resistance .4 to approximately the surge impedance of the antenna'for different frequencies and reduce to a minimum the residual curr nts which must be balanced out.

potentiometers 31, 32 and 33 and the amplifiers 11, 12 and 13, are replaced by couplers- 35, 36 and 37 having high impedance primary windings so as to constitute a small oadon the transmission line. In this case the circuits which include the secondaries 8, 9 and 10, and the secondaries ofthese couplers 35, 36 and 37 are tuned to the respec .tive frequencies to be received, and these 'separategircuits each select the particular si nalin iiurrent to be received therein wlthout' interfering with'the proper selection of the signaling currents by the other circuits.

While we have shown and described the,

preferred embodiments of our invention, it will be apparent that it is by no means limited to the particular circuit arrangements shown as many modificationsin the arrangement of' the circuits, the location of the receivingapparatus and the type of apparatus employed may be made without departing from the scope of our invention as set forth in the appended claims.

What we claimas' new and desire to se-' cure by Letters; Patent of the United States,.

'1. The combination in a radio receiving system; of an aperiodic receiving antenna, a plurality of receiving sets, means for lin pressing desired signaling currents of a plurality of different frequencies received upon said antenna upon said receiving sets,'an artificial transmission line associated with said antenna and means for impressing upon rality of different frequencies received upon.

said antenna upon. said receiving sets, an artificial transmission line associated with said antenna, means for impressing upon each of said receiving sets a current derived from said artificial line, and means for separately adjusting the phase and intensity of the currents impressed from the artificial line upon each of said receiving sets.

3. The combination in a radlo receiving system of a receiving antenna, a plurality of receiving sets, an artificial transmission line associated with said antenna and means for. impressing upon each of said receiving sets a current derived from saidiartificial line.

4. The combination in a radio receiving system of a receiving antenna, a plurality of receiving sets, an artificial transmission line associated withsaid antenna-and means for impressing upon each of said receiving setsa current derived fromsaid artificial line of the proper intensity and phase relation to neutralize the efiectof undesired currents in said receiving sets.

5. The combination in a radio receiving system of a receiving antenna, a plurality of receiving sets, an artificial transmission line associated with said antenna, means for impressing upon each of said receiving sets a current derived from said artificial line, and means for separately adjusting the phase andintensity of the currents impressed from the artificial line upon each of said receiving sets.

6.. The combination in a radio receiving system of an aperiodic. receiving antenna, a plurality of receiving sets, means for impressing desired si'gnaling currents of a plurality of different frequencies, received upon said antenna upon said receiving sets, an artificial transmission line associated with'said antenna and means for, impressing uponeach of said receiving sets a current derived from said artificial line.

7. The combination in a radio receiving system of an' aperiodic receiving antenna, a plurality of receiving sets, a plurality of circuits which are resonant to aplurality of different desired frequencies, an artificial transmission line associated with said antenna, and means for impressing upon each of said resonant circuits a current derived from said artificial line.

8. The combination in aradio receiving system of an aperiodic receivingantenna, a plurality of receivingsets, a plurality of circuits which are resonant to a plurality of difierent desired frequencies, an artificial transmission line associated with said antenna, and means for impressing upon each of said resonant circuits a current derived from said artificial line of the proper intensity and phase relation to neutralize the. efi'ect'of undesired currents in said resonant circuits.

9. The combination in a radio receiving system of an aperiodic receiving antenna, a plurality of receiving sets, a plurality of circuit's'which are'resonant to a plurality of different desired frequencies, an artificial transmission lin associated with said antenna, means for impressing upon each of said resonant circuits a currentderived from said artificial line, and means for separately adjusting the phase and intensity of the currents impressed from the artificial line upon each of said-resonant circuits.

10. The combination in a radio receiving system of an aperiodic receiving antenna, a plurality of receiving sets, a plurality of circuits which are resonant to a plurality of difi'ereut desired frequencies, means for imsaid antenna. upon said resonant circuits, an artificlal transmission line associated with sa1d antenna, and means for impressing upon each of said resonantcircuits a current rent .derived from the output clrcuit of onev derived from said artificial line. Y

' 11. The combination in a radio receiving system ofan aperiodic receiving antenna, a plurality of receiving sets, a plurality of c'ir-' cuits which are resonant to a plurality of difi'er ent desired frequencies, meansgior 1mpressing desired signaling currents; of-aplurality' of different frequencies received upon said antenna upon said resonant circuits,

' an artificial transmission line associated with said antenna, and means for impress- 1ng upon each of sa1d resonant circuits a current der ved from sa1d artificial line of the proper intensity andphase relation to'neu trahze the effect-of undesired currents in said resonant circuit;

12. The combination in a radio receiving system of an aperiodic. receiving antenna,'a plurality of receivmg. sets, a plurality of circuits which are resonant to aplurality; of difi'erentfrequencies, means for impressing de'slred si alingcurrents of a plurality of different requencies received upon said antenna upon said resonant circu ts,an artifi cial transmission line associated with said antenna, means for impressing upon each of.

said resonant circuits a current derived from sa1d artlficlal line, and means for separately adjusting the phase and'intensity of the ourrents impressed from the artificial line upon each ofsaid resonant circuits. 13. The'combination inaa radio receiving system of a receiving antenna, a plurality. of receiving sets, a plurality of electron, discharge amplifiers having input and output circuits, an artificial line associated with said antenna, means: for impressing upon each ofsaid in ut circuits a current derived from said art' current derived'from theoutput circuit ofone of said amplifiers.

receiving sets, a plurality of electron discharge amplifiers having input and output.

circuits, an artificial line associated with said antenna, means for impressing upon each of said input circuits current derived from said artificial line, means. for impressing upon each of said receivinglsets a current derived from the output circuitof one of said. amplifiers of the proper intensity and phase relation to neutrallzethe effect of undesired currents in each of said receiving sets.

' 15. Thecombination in audio receiving system of a receiving antenna, a plurality o 5 receiving sets, a plurality of electron 'discharge-amplifiers having input and output circuits, an artificial lme associated with cial line, and means for impressing upon each of sa1d receiving sets av said antenna, means for impressing upon each of said in ut c1reu1ts a current derived from said arti cial line, means for impressing-upon each-of said-receiving sets a ourof said amplifiers, and means for separately adjusting the phase, and intens ty 'of the currents impressed from the artificial hne upon each of said input circuits.

g 16'. The combination in aradio receiving system of a receiving antenna, a plurality of receiving sets, a plurality ofQelctron discharge amplifier's having input and output.

circuits, means, for impressing upon each of said input circuits desired signaling cur.- rents received upon said antennapan artificialline associated with said antenna, meansforimpressing u on eachofsaid input .circuits a current erived from said artificial line and means for impressing upon each ofsaid receiving sets a current derived from the output circuit of one of said amplifiers.

-. 17. The'combination in a radioreceiving system of a receiving antenna, a plurality line, meansfor impressing upon each of said receiving sets a current derived from the output circuit of one of said amplifiers of the proper intensity and phase relation to neutralize the efiect of undesired currents in each of said receiving sets.

18. The comb' ation in a radio receiving system of a receiving antenna, a plurality of receiving sets, I charge amplifiers having input and output circuits, means for impressing uponeach of said input circuits desired signaling curs. rentsreceived upon said antenna, an artificial line associated with said antenna, means for impressing upon each of said ina plurality of electron, discuits a current derived from said artificial 1 put circuits a. currentderived from said artificial line, means for impressing upon eachv of said receivmg sets a current der1ved from the output circuit-"of one of said amplifiers,

and means for separately adjusting the phase pressed from the artificial line of said input circuits; I a

.19. The combination in a'i'adio receiving system, of a receiving antenna, a plurality of receiving sets,

pon each and intensity of the currents 1ma plurality of electron disa charge amplifiers having input and output.

'circuitjs, means for impressing upon each of said input circuits desired'signaling currents're'eeived upon said antenna,-.an arti :ficial line associated with said antenna, separate means for impressing u on'each of sa1d input c1reu1ts a current erived from said artificial line, and'means for impressoutput circuits having a resonant circuit ing upon each of said receiving sets a current, derived from the output circuit' of. one of said amplifiers.

20. 'lhecombin'ation in a radio receiving system of a receiving antena, a plurality of receiving sets, .a plurality of electron dis charge amplifiers having input and output circuits. separate means for impressing upon each of said input circuits desired signaling currents received upon said antenna,- an artificial line associated with said-"antenna, means for impressingupon each of said input circuits a current derived-from said ar tificial line, means for impressing upon eachof said receiving sets a current derived fro.

the output circuit of one of said amplifiers;-

of the proper intensity and phase relation to neutralize the effect of undesired currents in each of said receiving sets, 1

21. The combinationin a radio receiving system of a receiving antenna, a plurality of receiving sets, a plurality of electron discharge amplifiers having input. and output circuits. separate means for impressing upon each of said input circuits desired signaling" currents received upon saidantenna, an ar'-' tificial line associated with said antenna, means for impressing upon each of said input circuits a current derived from'saidartificial line. means for impressing upon each of said receiving sets a current derived from the output circuitof one of said amplifiers, and means for separately adjusting the phase and intensity of the currents im-.

pressed from the artificial -line upon each of said input circuits. I 22. he combination in a radio receiving receiving-sets. a plurality of electron discharge amplifiers having-input and output circuits. an artificialline associated with Said antenna. means for impressing upon each of said inputcircuits a current derived from'said artificial line. and means foruimpressing upon each of said receiving sets a current derived from the 'output circuit of one of said amplifiers, said input circuits be ing aperiodic and each of said output circuits having a resonant elrcu t associated thereivith.

23. The combination in a radio receiving system of a receiving antenna, a plurality of receiving Sets. a pluralityof electron discharge amplifiers having input and output circuits. means for impressing upon each of said input circuits desired signaling currents received upon said antenna, an artificial line' associated with said antenna, means for inipressing upon each of said'input circuits. a current derived from said artificial line and means for impressing upon each of said receiving sets a current derived from the output circuit of one of said amplifiers, said input circuits being-aperiodic'and each of said associated therewith.

. .24. The combination in a radio receiving system of a receiving antenna, a plurality of receiving sets, a plurality of electron discharge amplifiers having input and output circuits, separate means for impressing upon each of said input circuits desired signaling currents received upon said antenna, an artificial line associated with said antenna, means'for impressingupon each of said inputcircuits a current derived from said artificial line, means for impressing upon each of said receiving sets a current derived from the output circuit of one of said amplifiers, and means for separately adjusting the phase and intensity of the currents im!- pressed from the artificial-line upon each of said input circuits, said input. circuits being aperiodic .and each of said output circuits having a resonant circuit associated therewit 2 5. The combination in a radio receiving system of a receiving antenna, a pluralityof receiving sets,- a plurality of electron discharge amplifiers having input and output circuits, means for impressing upon each of said input circuits desired signaling currents received upon said antenna, means for impressing upon each of said receiving sets a current derived from the output circuit of one of said amplifiers, and separate means for impressing upon each of said input cireuits a current derived from said antenna of suitable phase and intensity to neutralize in the receiving sets the, effect of undesired.

' currents therein.

- 26. The combination in a radio receiving system of a receiving antenna, a plurality of receiving sets, a plurality of eectron discharge amplifiers having input and output circuits, means for impressing upon each of said input-circuits two separate currents derived from said antennna, means for separately adjusting the phase and intensity of one of said currents, and means for impressing upon each of'said receiving sets a current derived from the output circuit of one of said amplifiers.

27. The combination in a-radio receiving system of an aperiodic receiving antenna, a plurality of receiving sets, a plurality of electron discharge amplifiers having apaniodic input circuits and output circuits, means for impressing upon each of said input circuits two separate currents derived from said antenna, means for separately adjusting thephase, and intensity of one of said currents impressed upon each of said input circuits, and means forimpressing upon each of said receiving sets the current derived from the output circuit of one of said amplifiers.

28. The combination in a radio receivinq system of a receiving antenna, a pluratite iteceivingsetspa plurality electrondisarge-amplifiers having input and output rcults, means for impressing upon each of id input circuitscurrents'derived from 'o difierent polnts m sa danten'na andreceiving sets, a plurality'of electron dis- .arge amplifiers having input and output rcuits, means f0r-'separately impressing )on each of said input 'circuits currents .deved from two difi'erent points in said annna, separte means for adjusting both the iase and intensity of one of the currents us impressed upon each ofsaid inputcir- -our hands this 26th da Fsa1d receiving sets a current erived from its, and means for impressin :uponeach .e output circuit of one of said amplifiers.

-30. The, combination in -a radio receiving system of an' aperiodic horizontal receiving antenna, a pluralit of receivin sets, a pluralityof electron discharge amp lfiers having aperiodic input circuits and output circuits, means for impressing upon each of said input circuit currents derived from two different points in said antenna, means for separately adjusting the phase and intensit of one of the currents impressed upon eac of said, input circuits, a. circuit associated with each of said receiving sets which is resonant to si nals to be received upon the set with whic itis associated, andimeans for impressing upon each of said resonant circuits a current derived from the output circuit of one of said amplifiers.

"In' witness whereof, we have hereunto set of A ril 1921.

EDWAR W. ELLOGG.

' CHESTER W. RICE. 

